Method of inserting a grummet or thimble in sail cloth or the like

ABSTRACT

A method of attaching a grummet to sail cloth in which two rings are positioned around the edge of a hole therein and are pressed into interconnection. The edge of the hole is first smeared with a setting glue and a short tube having a flanged end is placed in the die of a punch and one of the rings is placed around the tube on to the flanged end. The sail cloth is then placed on the tube and a second ring is placed on the ring above the sail cloth, the punch thereby deforming the tube so that it assumes a torus shape whereby the sail cloth is compressed between the rings and can then be removed from the punch.

o Unlted States Patent 11 1 1111 3,890,695

Gaastra June 24, 1975 METHOD OF-INSERTING A GRUMMET OR 2,553,051 5 1951Kingman 24 141 x THIMBLE IN S CLOTH OR THE LIKE 2,633,618 4/1953 Moe24/202 3,399,435 9/1968 Ackerman 24/241 Inventorr Douwe Gaastra, Heeg,Netherlands 3,512,224 5/1970 Newton 29/512 ux Assigneez Gaastra BDV,Sneek, Netherlands 3,653,353 4/1972 Davls 114/115 [22] Filed: Apr. 16,1973 Primary ExaminerChar1ie T. Moon [21] AppL N03 351,481 Attorney,Agent, or FzrmRobert F. O Connell [57] ABSTRACT Foreign ApplicafionPriority Data A method of attaching a grummet to sail cloth in May 8,1972 Netherlands 7206211 which two rings are positioned around the edgeof a hole therein and are pressed into interconnection. The [52] US. Cl.29/458; 24/ 141; 29/512; edge of the hole is first smeared with asetting glue 29/523; 72/391; 114/115; 156/88 and a short tube having aflanged end is placed in the [51] Int. Cl B23p 3/00; B23p 25/10 die of apunch and one of the rings is placed around [58] Field of Search 29/512X, 523 X, 458;;- the tube on to the flanged end. The sail cloth is then1 14/1 15 X; 24/141 X, 202; 72/391 X, placed on the tube and a secondring is placed on the 156/91, 88 X ring above the sail cloth, the punchthereby deforming the tube so that it assumes a torus shape whereby the[56] References Cited sail cloth is compressed between the rings and canUNITED STATES PATENTS then be removed from the punch.

2,393,984 2/ 1946 Gookin 24/ 141 2 Claims, 4 Drawing Figures PATENTEDJUN24 I975 SHEET [III/A07!!! 1 METHOD OFINSERTING A GRUMMET OR THIMBLE INSAIL CLOTH OR THE LIKE The invention relates to amethod of inserting agrummet or thimble in sail cloth or the like consisting of positioningtwo rings each at one side of the sail cloth around the edge of the holeand interconnecting both rings with the edge of the hole therebetween bypression. Grummets or thimbles serve for instance as points ofattachment for the sheets and the like in the corners'of a sail ofsailing boats or as points of attachment for lace or reef lines.

The prior art grummets consist of rings which are sewn in the sailcloth. the prior art thimbles consist of two specially formed ringswhich are pressed to one ring around the hole in the sail cloth.

The invention aims at providing a method of forming a grummet or thimblewhich is connected to the sail cloth in such a manner that each risk oftearing is exluded, it can be inserted in considerably less time thanthe prior art grummet and is considerably stronger than the prior artthimble. This aim is achieved according to the invention in that aftermaking the hole in the sail cloth or the like the edge of the hole isravelled out, the edge of the hole is smeared with a setting glue,preferably an epoxy glue, so that a glue smeared hole edge is formed. ashort tube is disposed in the die of a punch which tube preferablyconsists of stainless steel and has a diameter which fits into the hole,of which tube the lower end is somewhat flanged outwardly, one of thetwo rings which is preferably of aluminium is disposed around this tubeso that it rests on the outwardly flanged lower end of the tube, thesail cloth or the like is placed around the tube on the said one ring,the second identical ring is placed around the tube, the tube is sodeformed with the stamp of the punch that it obtains a torus-shapedconfiguration whereby the two rings clamp between them and compress boththe sail cloth and the edge, whereupon the sail cloth together with thegrummet or thimble is removed from the punch. After setting the grummetor thimble is at full strength.

Due to the fact that after the punching operation the edge forms a hardthickened rim which is entirely enclosed between the two rings and thetube which has been bent in the form of a torus an extremely strongconnection between the grummet or thimble and the sail cloth isobtained.

In a preferred embodiment of the method according to the invention thestamp of the punch, with a view to the removal of the sail clothtogether with the grummet or thimble from the punch, is built up of twodisengageable parts, the upper part of the stamp, after pressing thegrummet or thimble, being removed from the lower part. the lower partbeing laid on an anvil in such a manner that the bottom side of the dieis not supported and the grummet or thimble being pressed on or struckin order to move the die relative to the lower part of the stamp todiscontinue the wedging action between the grummet or thimble and thestamp.

The invention also relates to a punch for carrying out the methodaccording to the invention as well as to a sail for a vessel. tarpaulinor the like which is provided with at least one grummet or thimbleinserted with the method and/or the punch according to the invention.

The invention will now be further explained with reference to thedrawing in which:

FIG. 1 is plan view of a grummet or thimble accord- I ing to theinvention inserted in an opening in a sail or the like;

FIG. 2 is a cross-section along the line ll-ll in FIG. 1;

FIG. 3 is a cross-section through a ring;

FIG. 4 shows a longitudinal section through a punch for inserting thegrummet or thimble according to FIGS. 1 and 2 in a sail or the like.

Like every grummet or thimble, the grummet or thimble according to theinvention in plan view has the configuration of a ring which is disposedaround the edge of a round opening in the sail cloth which is indicatedat I.

In one way or another a round hole is made in the sail cloth. The edgeof this round hole is ravelled out for instance by means of a rotarysteel wire brush. Thereupon this ravelled edge is smeared with an epoxyglue or the like. After the punching operation this glue sets to athickened rim indicated at 2. On the rim, above or below the sail cloth1, a ring 3 of aluminium or the like is laid. This ring 3 is flat on oneside and has a circular cross-section at the other side. At the innerside of the ring 3 an edge has been removed. This edge has a boundarysurface 4 parallel to the plane of the ring and a boundary surface 5which tapers outwardly from the boundary surface 4 as shown in FIG. 3.

The edges formed by these boundary surfaces serve to receive the gluerim 2 of the sail cloth 1. Around the two identical rings 3 and the rim2, starting from a cylindrical. preferably stainless steel tube, acollar 6 is clamped, as illustrated in FIG. 1.

The insertion of the grummet or thimble according to FIGS. 1 and 2occurs in a punch which is illustrated in FIG. 4.

The punch comprises a die 7 having a central opening 8 and an upwardlyfacing channel-shaped recess 9. A stamp consisting of an upper part 10and a lower part 11, the so-called nipple, cooperates with the die 7.The nipple 11 has a threaded portion 12 which has been screwed into athreaded opening 13 in the upper stamp part 10.

The nipple 11 slightly tapers downwardly.

The upper part 10 of the stamp, as also the die 7, is provided with adownwardly facing channel-shaped recess 14.

The operation of punching the grummet in the punch according to FIG. 4takes place as follows:

The stamp is removed from the die.

The cylindrical stainless steel tube with its slightly outwardly flangedlower end is deposited in the channel-shaped recess 9 of the die 7.Hereon the lower ring 3 of the grummet or thimble is placed. Thereuponthe glue rim 2 of the opening in the sail cloth is placed in the removededge of the ring and on top of this the upper ring is placed.

Subsequently the stamp is inserted in the die and moved downwardlyrelative to the die.

The cylindrical tube is deformed to the collar 6 which tightly clampsthe rings 3 against the rim 2. Hereby the grummet has been formed.

Now the sail cloth together with the grummet or thimble must still beremoved from the punch. To this end first the upper part 10 of the stampis unscrewed from the nipple 11 which is wedged in the grummet.Subsequently the nipple is placed on an anvil with the lower edge of thedie 7 being no longer supported. By

now striking or pressing on the grummet and thence on the die thegrummet together with the die moves downwardly relative to the nippleuntil the wedging action due to the conicity of the nipple has beendiscontinued. The sail cloth with the grummet is then free from thepunch.

In this manner all the grummets in a sail of for instance a sailingvessel can be inserted.

It is clear that the method according to the invention can be applied inall sorts of domains. for instance in tarpaulins.

I claim:

1. A method for inserting a grummet or thimble in a material; such assail cloth or the like, comprising the steps of forming an opening insaid material;

ravelling the edge of said opening;

smearing said raveled edge with a thermosetting adhesive to form athickened edge about the opening;

positioning a first ring on a tube having a'flared end and an unflaredend so that said first ring comes to rest on said flared end;

inserting the unflared end of said tube into said opening so that saidunflared end projects therethrough and said first ring is placed incontact with one side of said material against the thickened edge ofsaid opening;

positioning a second ring on said projecting end of said tube so thatsaid second ring is in contact with the other side of said materialagainst the thickened edge of said opening;

and deforming the ends of said tube so that said tube assumes atorus-shaped configuration to tightly clamp the adhesive-smearedthickened edge of said opening between said first and second rings.

2. A method in accordance with claim 1 wherein said adhesive is an epoxyresin adhesive.

1. A method for inserting a grummet or thimble in a material, such assail cloth or the like, comprising the steps of forming an opening insaid material; ravelling the edge of said opening; smearing said ravelededge with a thermosetting adhesive to form a thickened edge about theopening; positioning a first ring on a tube having a flared end and anunflared end so that said first ring comes to rest on said flared end;inserting the unflared end of said tube into said opening so that saidunflared end projects therethrough and said first ring is placed incontact with one side of said material against the thickened edge ofsaid opening; positioning a second ring on said projecting end of saidtube so that said second ring is in contact with the other side of saidmaterial against the thickened edge of said opening; and deforming theends of said tube so that said tube assumes a torus-shaped configurationto tightly clamp the adhesivesmeared thickened edge of said openingbetween said first and second rings.
 2. A method in accordance withclaim 1 wherein said adhesive is an epoxy resin adhesive.